Previously we reserved 1024 bytes, but that's more space than the IOAPICconsumes, and it can cause conflicts with nearby devices. The knownrequirement is 68 bytes (sizeof(struct io_apic)), and rounding up to apower-of-2 gives us 128.

The bug reported below is caused by the following assignments (the IOAPICpower-on default and the watchdog address recommended in the AMD SP5100BIOS Developer's Guide):